Get the keys for duplicate values in an array

Question

I have the following array:

$myarray = Array(\"2011-06-21\", \"2011-06-22\", \"2011-06-22\", \"2011-06-23\", \"2011-06-23\", \"2011-06-24\", \"2011-06-24\",         


        

Answer 1

I'll answer the second question first. You want to use array_keys with the "search_value" specified.

$keys = array_keys($array, "2011-06-29")

In the example below, $duplicates will contain the duplication values while $result will contain ones that are not duplicates. To get the keys, simply use array_keys.

Result:

// $duplicates
Array
(
    [1] => a
)

// $result
Array
(
    [2] => b
    [3] => c
    [4] => d
)

// $unique_keys
Array
(
    [0] => 2
    [1] => 3
    [2] => 4
)

// $duplicate_keys
Array
(
    [0] => 0
    [1] => 1
)